If you have a model and you'd like to know where it came from, the .rsproj file has some clues.  The .rsproj is actually a zip file you can extract.  You can rename a .rsproj file to a .zip file and then extract it, or directly extract it with tools like 7Zip or WinRar.

There will be a number of files e.g

_CreatorMetadata.txt has a list of when the project was saved, what version of Source was used and in more recent versions, who saved it. This example is from a regression test we have had for a long time:

Comparing two models

If you have two models, you can use a diff tool to quickly find where models have diverged. I'd recommend WinMerg: https://winmerge.org as a diff tool.

You can also use the Export Summary (available under Tools \ Export Summary) then use a diff tool to see what parameters have changed between the two models.